Demonstrating group selection: A comment on Janet Landa’s ‘The bioeconomics of homogenous middleman groups as adaptive units’

Janet Landa provides an impressive historical tour of the development of her theory of homogeneous middlemen groups (HMGs), and how she arrived at the group selection approach. Despite her claim that the case studies she presents provide evidence for group selection in human societies, we argue that such a conclusion is premature. We suggest that an evolutionary explanation of HGMs will be strengthened by greater attention to the details of the selective process.